1. Field of the Invention
The present invention relates to a surface mounting type electrical jack having a plurality of terminals which correspond with contact strips provided in a body of the jack and are arranged with the lower surfaces thereof flush precisely or approximately with the bottom of the body. The contact strips of the jack are provided with contacts arranged respectively for contact with a plurality of axially spaced corresponding contacts of a plug which is inserted into the jack. Each terminal of the jack will be soldered to a circuit board in an overlapping arrangement in the pattern of a circuit.
2. Description of the Prior Art
A prior art surface mounting type jack is provided having contact strips arranged integrally on seat plates respectively which have corresponding terminals and are disposed in the interior space of a body of the jack. The terminals of their respective seat plates extend from slit openings provided in the side walls of the body to the outside of the same.
Such a prior art surface mounting type jack which has a plurality of slit openings provided in the side walls of a body thereof thus to allow the terminals to extend outwardly through the slit openings, needs to be arranged in which the slit opening are slotted open extensively from the rear end to the front end of the body for facilitating the insertion of the plural seat plates with the contact strips into the interior space of the body. However, the arrangement of providing a corresponding number of long slit openings to the terminals in the wall of the body will cause a decrease in the physical strength of the body. Particularly, for achievement of the reduced size of the jack by decreasing the wall thickness of the body, and thus maintaining the overall size to a minimum, it will be a great drawback to have the strength of the body decline due to the existence of the extensive slit openings.
Conventional jack of no mounting type are disclosed in Japanese Utility-model laid-open publication No. 48-27751 and Japanese Patent laid-open publication No. 61-82694.
A jack disclosed in publication No. 48-27751 is shown in FIG. 6 having a plurality of seat plates, which have contact strips respectively, all inserted through the rear end of a body 100 for installation within the body 100. The terminal 110 of each seat plate extends rearward from the rear end of the body 100. More specifically, the seat plates with the contact strips, except their respective terminals 110, are fully accommodated in the interior space of the body 100.
The jack disclosed in the Japanese laid-open publication No. 61-82694 is shown in FIG. 7. The jack includes a plurality of U-shaped metal members 120, each of which has a couple of leg portions 122, 122 bent along both ends of a center portion 121 thereof, arranged along the length of and fitted astride each other onto a body 100' of the jack. The center portion 121 of each U-shaped metal member 120 incorporates a contact point 123 provided at a given place thereof and extending to the interior space of the body 100' through an opening arranged in the upper surface of the same. More particularly, the U-shaped metal members 120 provided with the contact points 123 and having also terminals 124 extending from the leg portions 122 thereof are all disposed in the outside of the body 100', but excluding their respective contact points 123.
When the prior art described in publication No. 48-27751 is applied to a surface mounting type jack, an advantage is that it is unnecessary to have openings arranged in the body for the terminals extending through. However, since the plural seat members with the contact strips are all disposed within the body except their respective terminals 110, there is needed an extensive space in the body for accommodating the desired number of the seat plates with the contact strips. When the jack is reduced in size, such an interior space is no longer available and the positioning of the contact strips relative to the contact points of a plug to be inserted into the body will thus be troublesome. Hence, it is not a good idea to use the prior art described in this publication for further reduction of the size of a surface mounting type jack.
The jack described in publication No. 61-82694 is arranged in which the U-shaped metal members 120 with the terminals 124 extending from the leg portions 122 are all disposed on the outside of the body 100' but excluding their respective contact points 123 which extend into the interior space of the body 100'. Accordingly, as the number of the contact points 123 increases, the metal members 120 are increased in number and thus, the length of the body 100' will never be shortened limiting the size reduction of the jack. If the metal member 120 is reduced in width for reducing the overall length of the body 100', the urging force of the planar portion 121 of each U-shaped metal member 120 will decrease. When the urging force is lowered, the contact pressure of the contact point of the U-shaped metal member 120 against the contact of a plug which is inserted into the body 100' will decrease and consequently, the contact reliability will decline. Also, it is not a good idea to employ the prior art described in this publication for reducing the size of a surface mounting type jack.